From e1314898de28d1c7354df6a06eb53e4095f1928f Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Tue, 28 Feb 2023 20:56:32 -0800 Subject: [PATCH v7 01/14] Don't initialize page in {vm,fsm}_extend(), not needed The read path needs to be able to initialize pages anyway, as relation extensions are not durable. By avoiding initializing pages, we can, in a future patch, extend the relation by multiple blocks at once. Using smgrextend() for {vm,fsm}_extend() is not a good idea in general, as at least one page of the VM/FSM will be read immediately after, always causing a cache miss, requiring us to read content we just wrote. Discussion: https://postgr.es/m/20230301223515.pucbj7nb54n4i4nv@awork3.anarazel.de --- src/backend/access/heap/visibilitymap.c | 6 +----- src/backend/storage/freespace/freespace.c | 5 +---- 2 files changed, 2 insertions(+), 9 deletions(-) diff --git a/src/backend/access/heap/visibilitymap.c b/src/backend/access/heap/visibilitymap.c index 11e6d0d479f..114d1b42b3e 100644 --- a/src/backend/access/heap/visibilitymap.c +++ b/src/backend/access/heap/visibilitymap.c @@ -622,11 +622,9 @@ static void vm_extend(Relation rel, BlockNumber vm_nblocks) { BlockNumber vm_nblocks_now; - PGAlignedBlock pg; + PGAlignedBlock pg = {0}; SMgrRelation reln; - PageInit((Page) pg.data, BLCKSZ, 0); - /* * We use the relation extension lock to lock out other backends trying to * extend the visibility map at the same time. It also locks out extension @@ -662,8 +660,6 @@ vm_extend(Relation rel, BlockNumber vm_nblocks) /* Now extend the file */ while (vm_nblocks_now < vm_nblocks) { - PageSetChecksumInplace((Page) pg.data, vm_nblocks_now); - smgrextend(reln, VISIBILITYMAP_FORKNUM, vm_nblocks_now, pg.data, false); vm_nblocks_now++; } diff --git a/src/backend/storage/freespace/freespace.c b/src/backend/storage/freespace/freespace.c index 3e9693b293b..90c529958e7 100644 --- a/src/backend/storage/freespace/freespace.c +++ b/src/backend/storage/freespace/freespace.c @@ -608,10 +608,9 @@ static void fsm_extend(Relation rel, BlockNumber fsm_nblocks) { BlockNumber fsm_nblocks_now; - PGAlignedBlock pg; + PGAlignedBlock pg = {0}; SMgrRelation reln; - PageInit((Page) pg.data, BLCKSZ, 0); /* * We use the relation extension lock to lock out other backends trying to @@ -649,8 +648,6 @@ fsm_extend(Relation rel, BlockNumber fsm_nblocks) /* Extend as needed. */ while (fsm_nblocks_now < fsm_nblocks) { - PageSetChecksumInplace((Page) pg.data, fsm_nblocks_now); - smgrextend(reln, FSM_FORKNUM, fsm_nblocks_now, pg.data, false); fsm_nblocks_now++; -- 2.38.0